Comparing led grow lights to other types

I have considered trying out a couple of LED grow lights. I currently have an eight tube 4-foot T5 fluorescent, and have used metal halide in the past.

The problem is, I really have no idea how to get a feel for the true light output (PAR or otherwise) of most of these fixtures.

So many of them have fake wattages that are supposed to represent the “equivalent“, but no lumen ratings or anything.

I know lumens are not the best measure, but they are the one I am familiar with. I know my T5 puts out 33k lumens (more or less). I know how well things grow under it, what I can grow, and how far away I need to put the light.

With these LED fixtures I have no point of reference to know where to even start, if it’s actually worth the money, etc. etc.

Here’s an example. It’s not “4000W”, that’s marketing BS. Yet even the true input wattage isn’t clear, it’s either 640W or 385W. The actual PAR or lumen output? Who the heck knows? Just based on the price, I am assuming this is a heck of a lot more powerful than my fluorescent, but I don’t really know. I have no way of figuring that out with the information provided.

Am I missing something, or do other people find this as frustrating and difficult as I do?

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Yea we had a thread about that last year. Never figured it out myself. But i did have good results with my Aliexpress fixtures.


If I can find some thing in a store I could go in with a light meter, but 90% of the stuff is online, and I wouldn’t even know where to look at one in person!

I used LED for starting seeds and keeping my grape cuttings alive until I could get them planted out. You can put them a lot closer to the plants than HPS or MH and they are way cheaper. You can download apps to check lighting for a comparison. Here is what I got and how I used it.

Grow Light Strip, 2ft T8 Grow…

Oh and I would say what I got was better than my 400 wt HPS.

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Even these comparison websites are crap. It’s basing the “equivalence“ on a 1000 W metal halide being about 40,000 lumens, when in reality, they’re more like 110,000.

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I just ordered 4 sets of these a few days ago.

You can’t go wrong with the price, 14 bucks for 2 sets of led shop lights. I plan to use them for seed starting and getting some plants through the winter, then back outside. If I was trying to get things to flower I’d add different spectrums based on the thread last time around. It’s all so confusing and as you say the numbers just don’t make sense with the “equivalent watts” shenanigans they pull.

I am paying forward some info that may or may not be interesting to some of you… i have done it myself with great results…but i am no electrician or expert… just a trial and error guy.

Go to wherever they sell LED light bulbs and get the 100W daylight bulbs.

With a knife or something pry off the plastic end of the bulb that is barely glued on.

Enjoy some super rich intense light for cheap.

Its not my idea nor my advice to do it… there used to be youtube videos on it which is where i got the idea…

It works for me but YMMV.


You can buy Led bulbs for your fixture. Maybe start there. I have heard the 600 watt models is what you want. Joe Lamp’l has a gardening podcast. The joe gardener show. One episode covers leds quite well.


I’m sure the fixture you linked from Amazon would put out a lot of light. I have no idea how much but enough for many uses. That unit covers about 43x45 inches.

What I’ve been using is what are probably similar light strips but independent units 4ft long that can be spaced out as needed. So this item for 1/3 the price has eight 4ft LED strips that I usually space 16-24 inches apart: : Kihung LED Grow Light Strips, 4FT T8 Grow Light, 336W(8×42W) Full Spectrum Grow Light with Reflectors, High PPFD Value Plant Light for Indoor Plants, 8-Pack : Patio, Lawn & Garden

Those eight strips at my spacing cover an area 4ft by 12-16ft. That’s enough to carry fig cuttings for the first 3 months of rooting and growth.

So less than 1/3 the price and 3-4 times the coverage. But maybe not enough light for your needs.

Yep, exactly what I use except I use the 2 foot version. They are quite bright, and work great for cuttings and seeds.

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ive done that and it works pretty good for cheap. get a screw in 4 way splitter and 1 light fixture covers a 4ft-5ft area. use a ceramic socket one for safety. they can handle higher wattage. works much better that those bigger muti colored flood grow light bulbs.

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@steveb4 i am kind of frugal and like to make my own stuff instead of the chinese amazon stuff when i can. Good idea on the splitter… i used a 4 bulb vanity light that i found at a thrift store… kinda the same thing.

I think the idea came from the dudes growing ‘weed’ in their closets in apartments… keep it hidden but also be growing on the downlow… at least thats what i gathered from the youtube videos.

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I bought a few of these on sale a little bit ago, similar concept to the 100 watt equivalent lights (14 watt actual) that put out 1500 lumens. These are 30 watt fixtures that put out 3500 lumens. I know that isn’t the best metric for what we are looking for but if you want to pack in the light for a small space using regular bulbs instead of light strips, these may be the ticket.

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i agree. im not a fan of anything chinese. i did get the idea from a friend that used to grow weed illegally back in the day. he used 8 100w equivalent led bulbs to grow out 1 weed plant and got pretty good yields in his closet grows.

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One of these will help you understand the absolute light levels in terms of energy available to your plants. I have sodium vapor lights and LED’s. Each has their place for sure.

I hope this note will give you some hope when it comes to over wintering your plants and starting seedlings. I’m a general gardener in the mid south and I started out using these fancy pot growing LED multicolored fixtures to get my citrus plants through the winter. Worked great but EXPENSIVE!!! I talked with Mike McGrath in Bethlehem, PA several years ago about this. Mike has a good radio show on NPR, You Bet Your Garden. He’s been a master gardener for many years. He told me not to waste my money on the expensive stuff and go for the regular fluorescents. Just recently I heard him say he was converting over to LED shop lights (just plain 3,000K daylight). I converted a few years ago and now have about fifteen of those double tube four foot units hanging from the rafters on individual pulleys to get the right distance from the different cultivars I have in my basement garage. I have them plugged into each other in series and on a timer so they burn a total of 16 hours a day with 8 hours total of darkness. I have one grapefruit, three Meyer lemons, three key limes, and a host of overwintering plants and seedlings such as contender peach seedlings and Meyer seedlings under the lights. They are all doing very well. They’re producing new growth with new blossoms and fruit set as well after hand pollination. The grapefruit, which I was concerned about, went crazy under the lights. Flowering all over the place…very excited about that one. I go down there everyday to applaud them for their growing efforts. I’ve harvested a dozen lemons so far with a lot still left on the bushes. My olive and curry trees are looking very promising as well. So keep doing what your doing. Watch the watering over the winter. I monitor all my plants and get a pretty good feel for when to add water. Hope that helps.


I run mine 24/7. The same or similar lights. 24/7 is easier and the plants so far enjoy the extra light. 24/7 hasn’t bothered anything.

I also have one of the $400 lights that covers about 3x5ft. It’s much brighter but my plants don’t seem to care.

Mostly figs and pineapple at this time.

I had so so luck with a sansa bulb in a clamp light. My girlfriend had bought me an led light with octopus arms and that didn’t work the best.

I bought a MARS HYDRO TS-1000 Led Grow Light 3x3ft Coverage. And it worked excellent. was able to start all my seeds and had pretty good results.

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I wonder how much research has been done to determine what is “enough” light for specific purposes (seed starting, cuttings propagation, flowering, fruiting etc) as I’m sure there are varying needs. I have kept a small light on 24/7 for some plants to overwinter but I know it isn’t enough, so I upgraded this year.